Three men were executed by Hamas in Gaza on suspicion that they were collaborating with Israel, while another seven were also arrested by security personnel in the Strip, a Hamas-linked news site said Thursday.

The arrests and executions apparently came in a crackdown after three top Hamas officials were killed in an Israeli air strike on Wednesday night, the Palestinian Ma’an news agency reported, citing the al-Majd website.

The report said that the three men were tried under “revolutionary procedures.” The website also declared a “zero-tolerance” policy toward those who collaborate with Israel.

Israel has carried out airstrikes against a number of high-level targets in Hamas’s leadership over the last two days, including an airstrike aiming for Hamas armed wing commander Muhammed Deif. It is not clear if Deif survived the attempt.

Last month, at the height of the IDF’s Operation Protective Edge in the Gaza Strip, a Palestinian media source reported that Hamas had killed over 30 suspected collaborators.

Unnamed Palestinian security sources in Gaza told Palestine Press News Agency that Hamas had apprehend dozens of suspected spies in the northern neighborhood of Shejaiya — which saw heavy fighting with the IDF during July — and summarily executed them following a short investigation. The sources said that many of the suspects were caught with weapons, telephones, and SIM cards from the Israeli cell provider Orange.

According to Ma’an, another man suspected of working with Israel was shot dead in the middle of the day on a Rafah street, in southern Gaza, on July 13.

Hamas has undertaken numerous anti-collaboration campaigns in the Gaza Strip over the past years, offering amnesty to repentant Israeli spies. In May, the Hamas government executed two condemned collaborators for divulging information which Israel used to kill two Palestinians.